Electric switch



Nov. 30, 1937.

v. R. DESPARD ELECTRIC SWITCH Filed pril 6. 1934 Patented Nov. 30, 1937 Victor B. Despa Syracuse, N.

Pass & Seymour, Inc., Syracuse,

ration of New York Y., assignor to N. Y., a corpo- Application April 6, 1934, Serial Io. 719,383 12 Claims. (crew-oi) This invention relates to electric switches and;

particularly to switches of'the type used in the wiring*of residences, stores, omce buildings, and the-like, mounted behind wall plates and used mainly for the control of lights, small motors,

and household appliances.

The invention is particularly applicable to switches of the type intended for use in combination assemblies of wiring devices or multiple units of switches as particularlydisclosed in my Reissue Patent No. 19,092, granted February 20, 1934, and provides improvements in such switches for that purpose as shown in the patent to Russell algid Despard No. 1,948,399, granted February 20, 1 34.

It is a general object of the present invention to provide, in such switches, novel and improved mounting means thereof More particularly it is an object of the invention to provide means whereby the closure plate, which is formed of insulating material, takes part of the strain of the wiring as applied to the terminals and relieves, to that extent, the housing of the switch which, by virtue of its peculiar size and shape limitations, is relatively fragile.

Another feature of the invention resides in the construction of a snap switch including an insulating housing having an insertion of switch operating mechanism and switch contacts, together with supporting means for these contacts and their associated terminals, which means are carried jointly by the housing and by an insulating closure for the rear thereof. Other and further features and objects of the invention will be more apparent to-those skilled in the art upon a consideration of the accompanying drawing and following specification wherein are disclosed several exemplary emscope thereof. It will be understood that such changes and modifications may be made in the various features illustrated such as fall within the scope of the appended claims without departing from the spirit of the invention.

In said drawing:

Figure 1 is a side elevation, partly broken away, of a switch constructed according to the present invention shown assembled in a mounting strap;

Figure 2 is an end elevation thereof having a portion broken away of the terminal carrying plate and the closure;

.Figure 3 is a rear elevation thereof with a portion of the closure and its securing means broken 3 SW;

for the contacts and terminals open, rear for .the

bodiments of the invention illustrating the generic to illustrate the connection "switches, which requires that each There results a considerable strain on the termioutside of the box and must then to Figures 1-4 inclusive,

Figure 4 is an elevation of a contact'andterminal carrying plate; Figure 5 is a view similar to Figure 1 illustrati'ng a different embodiment of the invention:

Figure 6 is-a view similar to Figue 3 but illus-' s trating the embodiment of Figure 5; and

Figure 'I is a view similar to Figure 4 illustrating 'a modified form of contact and terminal carrying plate and itsassociat'ed parts. i In the above identified reissue patent there is disclosed a system. of arranging and mounting wiring' apparatus of the type referred to, wherein a plurality of wiring devices are assembled in the space usually occupied by a single one, specifically, three wiring devices in the conventional space allotmentof a single gang outlet box. At times all three of these devices may be individual switch should conform to very definite space limitations. Nevert eless each switch must be able to handle relatively high currents andcomply with the quite rigid specifications of the Underwriters? Laboratories. Such switches asnow con- I structed are capable of handling sufficient current to require connecting wires as large as No. 12 B. & S. gauge. Such wire is relatively stiff and unyielding and is attached to switches in their assembled form on mounting bridges prior to the insertion of the assembly into the outlet box.

ham and their supporting means when the assembly is inserted into the box because the wires are always sufflcientlylong to permit wiring be bent and stowed in the box as the assembly is moved into position. The bending results from pressure on the assembly and resistance at the attachment of the wires to the box wall. Sometimes the bends are quite short and the strains considerable. It has been found that where the switch shell or caswhich is formed of molded insulating mate-. rial, is solely relied on to take the strains, breakage sometimes occurs, particularly since the space. 5 limitations are such that the shell cannot be made as strong as manufacturers would like. It has been found that the rear end of the shell, which takes the major strain, is the part that most often succumbs to it, so in accordance with the present invention a portion of this strain is transferred to the closure plate to be more uniformly applied to the shell, and localized strains resulting in cracking are largely eliminated.

Referring now to the drawing and particularly there is shownat I0 a mounting strap of the type intended to span the 5s to prevent its movement except in its vices which are attached thereto, preferably interchangeably, in any dxired manner. I switch is shown attached to the strap.

The switch I3 the passage of the switch operator this instance operates a mechanism type.

Integral with the front walls I1 01' the toggle a plane 2|, and open, permitting access to the interior.

Switch mechanism of suitable form, for instance as shown in Patent No. 1,948,399, is insertable through the rear opening of the shell with its handle l6 passing through the opening in the handle l6. This sector carries contacts or bridging members as required by the nature of the circuits to be controlled by the switch, and these movable contacts cooperate with. at least a pair of stationary contacts.

While the switch may be constructed for singlepole, double-pole, three-way, and four-way opslots is'shown at 3| in Figure 3 and is of sumcient length to outer abutment 34 seen at the left where a portion or the housing is broken away.

be provided on its outside i'ace with a strap ii 01' side of Figure 3 The rear portion of cause of the relatively large notch 35 cut in the a closure member 38, preferably formed of laminated insulating material to have considerable tenacity. It has a configuration a projection cover plate.

rectangular plate 50 shown in Figure '7, and-this is set into the shell through the rear and par- This plate may theterminal and the contact. Instead of this assembly being mounted in slots in the side walls of the shell, its forward edge has engagement with the shell or a projection on the shell. Conveniently this may take the form of one or more lug-like projections 55 extending from the forward edge, which projections are received in recesses 56 formed in bosses 51 molded integral with the end walls of-the shell as seen in Figure 5.

The rear edge of this insulatingplate 50 carries one or more lug-like projections 58 which are received in openings 59 in the cover plate 60 which may be attached in the manner previously described. The end walls 6| of the shell are notched as at 62 to expose the heads of the terminal screws, and corresponding notches 63 are out in the closure plate. These are true notches rather than a removed corner, as in the first embodiment, and leave material for a pair of the lugs 58 to be received.

In this embodiment, asin the first one, it will be seen that the forward end of the contact carrier is attached or mounted in the housing whereas the rear edge thereof is secured to and positioned by the closure plate. In this manner substantially all strain from the rear edges of the walls of the housing is eliminated. Where the attachment of the forward edge of the contact carrying plate is made, the housing naturally has greater strength by reason of its association with the front wall.

It will be appreciated that where the invention of the first embodiment is applied to such switches as have more than one contact at each end, as in the double-pole, three-way, and four way types. only the rearmost contact carrier plate will have a lug engaging the closure plate, but in the event of using the embodiment of Figures 5, 6, and '7, the insulating carrier plate can be provided with two sets of terminal screws and two contacts which will, of course, be insulated from each other. A further advantage of the construction of Figures 5, 6, and '7 is that where a double contact assembly is provided, it can be inserted without removing the forward terminal screw which is exposed as shown in Figure 7 of Patent No. 1,948,399 through an opening in the end wall not connected with the rear opening in the shell. This cannot be done where the supporting plates are slid into grooves as in that patent.

iii

The necessary changes in the devices as shown to accommodate them to other than single-pole contacts will be obvious from an inspection of Patent No. 1.948.399.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a switch of the type described, in combination, a shell of insulating material having side walls, a front wall perforated for a switch operator, and an open back, a contact and terminal screw support near one end of the shell, interengaging means on the support and shell to position one end of the support means in the shell, a closure sheet of insulating material for the rear opening of the shell, means securing shell, said closure sheet having a recess pressed into its under surface and a projection on said support fully and closely housed in said recess to position the opposite end of the support in respect to the shell.

2. In a snap switch, in combination, a shell of moulded insulating material having side walls,

end walls, a front wall and an open' back, a

closure plate for said back formed of tenacious insulating material, means to securely fasten said plate tosaid shell, a contact carrying member extending along each end wall and having a part cooperating directly with said shell for support thereon, another part ofsaid member entering said plate a distance less than the thickness of the plate for cooperation therewith.

3. In a snap switch, in combination, a shell of molded insulating material open at its rear for the insertion of switch mechanism and having a front wall, side walls and end walls, an insulating cover plate adapted to be securely fastened over said open rear, a contact and terminal support adjacent each end wall, a portion on each support engaging in a recess in the shell, a portion on each support engaging in a close fitting recess in said cover plate, said cover plate having other engagement with the supports to maintain them in the shell, each support having a switch contact and a terminal screw member associated therewith,

-4. In a snap switch of the type adapted to be assembled with two other wiring devices in the space of a single gang outlet box, in combination, a shell ofmoulded insulation adapted to be assembled with a mounting strap, said shell being substantially rectangular in sections parallel to the plane of said strap and including a front wall, connected side and end walls and an open rear, a cover for the rear adapted to be secured to the shell, a support mounted in the shell substantially parallel to and near each endwall thereof, a contact and a terminal screw on each support, means on each support received in otherwise closed recesses in the shell and coverto'retain the support rigidly in position,

a notch in each end wall for access to the terminal screw on its associated support, and switch mechanism in said shell to cooperate with the terminals on the supports.

5. In a snap switch, in combination,

of molded insulating material having sidewalls,

, end walls, a front wall perforated for a switch an opening in the adjacent end wall for access to said terminal screw,

a switch mechanism a shell having a frame in said shell, a closure of insulating material for said back opening, means securing said closure firmly to the s hell, alug on said support member, and a recessinsaid closure snugly receiving said lug, said closure engaging another portion of the contact support member and the frame to hold them in the shell.

6. In a snapfswitch, in combination, a shell of insulating material having walls, a front wall perforated for a switch operator, and an open back, a groove extending from the back toward the front in each side wall adjacent each end wall, a contact support' member extending from groove to groove across the shell adjacent each end wall and slidable into positon through the open back, a contact on each member extending toward the interior of the shell, a notch in each nicating with the open rear of the shell, a terside walls, end

end wall commuminal screw projecting outwardly from each.

member and received into said notch'as the memher is slid into position, a closure for said rear ly engage each lug.

8. In a snap switch, in combination, a shell of insulating material having side walls, a front wall engaging the rear edge of each plate to hold it in the shell and having a recess to wholly receive each lug.

9. In a switch of the type described, in com nation, a shell of side walls, a front insulating material having wall perforated for a switch of said shell, means on the rear of said support extending into said closure whereby the support is fixed at opposite edges in reshell of insulating spect to the shell and a ing into said support.

10. In an electric switch, in combination, a material having an apertured front wall and an open back for theinsertion of switch mechanism, .a combined contact and wire terminal device within the shell and adjacent an end thereof, the wire terminal portion of the determinal screw extendvrc'ron R. DESPARD. 

